Tench Welfare: Still-Water Specialists and Their Seasonal Behaviour

Tench are powerful, thick-set fish of still and slow-moving waters. Their late-night and early-morning feeding behaviour creates specific angling welfare considerations.

Key Facts

Tench are distinctive for their small scales embedded in thick protective mucus and their small red eyes
They feed primarily at dusk and dawn in summer, making them predominantly a twilight angling target
Tench are hardy fish that tolerate low oxygen conditions better than most cyprinids
Their thick mucus layer provides protection but is damaged by dry hands or rough handling
Tench spawn in early summer in dense weed beds — disturbance during this period causes reproductive disruption

Welfare Considerations

Tench welfare in angling centres on protecting their distinctive mucus layer, which provides immunity and thermoregulation functions. Handling with dry hands removes mucus and leaves fish vulnerable to fungal infection. Rough landing net mesh and hard bank contact also abrade the mucus layer. Their tolerance of low oxygen does not mean they are unaffected by angling stress — cortisol responses are well documented in cyprinids regardless of oxygen tolerance. Early-morning sessions should avoid spawning areas in May and June.

What You Can Do

Wet hands thoroughly before handling tench to protect their mucus layer
Use soft-mesh landing nets that minimise mucus abrasion
Avoid fishing in spawning areas during May and June when tench are breeding
Release tench gently and support their full weight during any brief handling